#include <stdio.h>
int main(void)
{
	int n, m;
	char letter[20];
	char first = 'F';
	for (n = 1; n < 7; n++,first--)
	{
		letter[n] = first;
	}
	for (n = 1; n < 7; n++)
	{
		for (m = 0; m < n; m++,letter[n]++)
		{
			printf("%c",letter[n]);
		}
		printf("\n");
	}
	return 0;
}